In the high deserts of the Great Basin there is a popular ornamental called Russian Sage (No one seems to know the genus or species or variety. It looks like the pictures of Russian Sage at images.google.)

Last fall or early winter I trimmed mine and buried the lower ends of a few dozen cuttings in a trench about six to eight inches deep. That's it. Nothing more.

About half of them now have roots and shoots. All those that have roots and shoots are older, longer cuttings with rough bark on the lower half. Younger cuttings with smother bark the entire lenght have no roots or shoots.